A hydraulic actuating device for a friction clutch and a gear setting element has a power unit for pressure generation by use of an electrically driven pump. Gear setting and clutch actuating sections are hydraulically connected to the power unit. A detenting device with a blocking element is associated with a piston of the clutch setting cylinder, which is operatively connected with the friction clutch and can be hydraulically loaded on opposite sides. The blocking element is resiliently biased into a blocking setting preventing piston movement and is movable by an actuator from the blocking setting into a release setting permitting piston movement. The pump is reversible in order to load the piston on one or the other side for an actuating movement. The control unit coordinates activation of the pump and actuator in order to disengage or engage the friction clutch.

A transmission system (10) includes a first piston (12), a second piston (14) and a modulator piston (16). The first piston (12) receives an input force (F.sub.IN), the second piston (14) transmits an output force (F.sub.OUT), and the modulator piston (16) transmits a modulating force (F.sub.ACT>which modulates the input force (F.sub.IN) received by the second piston (14) to implement tremor cancellation and force and/or provide variable motion scaling.

A transmission system (10) includes a first piston (12), a second piston (14) and a modulator piston (16). The first piston (12) receives an input force (F.sub.IN), the second piston (14) transmits an output force (F.sub.OUT), and the modulator piston (16) transmits a modulating force (F.sub.ACT>which modulates the input force (F.sub.IN) received by the second piston (14) to implement tremor cancellation and force and/or provide variable motion scaling.

An electric motor (2) is controlled according to the stroke of an input rod (30) moved in response to an operation of a brake pedal. The rotation of the electric motor is transmitted through a belt transmission mechanism (45) to a ball-screw mechanism (38) to propel a primary piston (10), thereby generating a brake hydraulic pressure in a master cylinder (4). The belt transmission mechanism has pulleys (45A, 45B), one of which is secured to an output shaft of the electric motor. The output shaft and a nut member (39) of the ball-screw mechanism are held by bearings (42A, 42B and 42C) secured to a rear housing (3B) which is a single member. Thus, before an electric motor-driven booster (1) is assembled, the belt transmission mechanism can be subassembled to the rear housing. Therefore, a belt (46) can be adjusted for tension in the state of a subassembly.

An electric motor (2) is controlled according to the stroke of an input rod (30) moved in response to an operation of a brake pedal. The rotation of the electric motor is transmitted through a belt transmission mechanism (45) to a ball-screw mechanism (38) to propel a primary piston (10), thereby generating a brake hydraulic pressure in a master cylinder (4). The belt transmission mechanism has pulleys (45A, 45B), one of which is secured to an output shaft of the electric motor. The output shaft and a nut member (39) of the ball-screw mechanism are held by bearings (42A, 42B and 42C) secured to a rear housing (3B) which is a single member. Thus, before an electric motor-driven booster (1) is assembled, the belt transmission mechanism can be subassembled to the rear housing. Therefore, a belt (46) can be adjusted for tension in the state of a subassembly.

A hydrostatic actuator and an arrangement for attaching it to a receiving component are provided. The hydrostatic actuator has a master cylinder containing a housing and a piston movable axially within the housing which acts on a pressure chamber filled with a pressurizing agent. The piston is driven by a rotary-driven electric motor having a stator and a rotor, by a rolling planetary transmission that converts the rotary drive to an axial motion. In order to be able to produce such a hydrostatic actuator with little need for construction space, cost-effectively and with better quality, a supporting of the rolling planetary transmission is simplified, and the cooling and shielding of an electronic controller and the pressure behavior of the hydrostatic actuator is improved.

A hydraulic pressure generating device includes a base body having a master cylinder configured to generate a brake hydraulic pressure and a slave cylinder configured to generate a brake hydraulic pressure. The base body is provided with a motor configured as a driving source for the slave cylinder and a control device configured to control the motor. A motor shaft of the motor, a cylinder axis of the master cylinder, and a cylinder axis of the slave cylinder are disposed in parallel with each other. Then a virtual plane including the cylinder axis of the master cylinder is set as a reference plane, a housing of the control device is disposed on one side of the reference plane and the motor is disposed on the other side of the reference plane.

A hydraulic pressure generating device includes a base body having a master cylinder configured to generate a brake hydraulic pressure and a slave cylinder configured to generate a brake hydraulic pressure. The base body is provided with a motor configured as a driving source for the slave cylinder and a control device configured to control the motor. A motor shaft of the motor, a cylinder axis of the master cylinder, and a cylinder axis of the slave cylinder are disposed in parallel with each other. Then a virtual plane including the cylinder axis of the master cylinder is set as a reference plane, a housing of the control device is disposed on one side of the reference plane and the motor is disposed on the other side of the reference plane.

Pulse controlled linear actuator comprising a working cylinder (9) for receiving a medium introduced through a valve system by a compressor/pump, a piston, the shank (13) of which represents the output of the actuator. It also comprises a central solenoid (1) and alternately moved iron cores (3). The central solenoid (1) and the iron cores (3) are arranged between upper and lower solenoids (2). The iron cores (3) have two separate medium spaces (14, 15). The first medium space (14) leads into the portion of the working cylinder (9) above the piston (10) and under the piston (10). The second medium space (15) is separated from the space between the iron cores (3) by the iron cores (3) and leads into the portion of the working cylinder (9) above the piston (10) and under the piston (10). The valves (4, 8) are counter-phase or phase pulse controlled.

Pulse controlled linear actuator comprising a working cylinder (9) for receiving a medium introduced through a valve system by a compressor/pump, a piston, the shank (13) of which represents the output of the actuator. It also comprises a central solenoid (1) and alternately moved iron cores (3). The central solenoid (1) and the iron cores (3) are arranged between upper and lower solenoids (2). The iron cores (3) have two separate medium spaces (14, 15). The first medium space (14) leads into the portion of the working cylinder (9) above the piston (10) and under the piston (10). The second medium space (15) is separated from the space between the iron cores (3) by the iron cores (3) and leads into the portion of the working cylinder (9) above the piston (10) and under the piston (10). The valves (4, 8) are counter-phase or phase pulse controlled.